(1) Field of the Invention:
This invention relates to the structure of an outer tube for guiding a drive member which is adapted to drive a webbing of a passive seat belt system for an automotive vehicle.
(2) Description of the Related Art:
A conventional passive seat belt system is illustrated by way of example in FIG. 5. A rail 8 is provided on an inner roofside 7 of a vehicle, whereby the rail 8 generally extends along a longitudinal axis of the vehicle. A slider 50 is provided in such a way that the slider 50 is allowed to move freely within the rail 8 along the longitudinal axis of the vehicle. A webbing 20 of the seat belt system is fastened to the slider 50, and the slider 50 is driven by a drive member composed of a tape, wire or the like arranged inside the rail 8. When an occupant wants to egress from the vehicle, the slider 50 is driven forward to move the webbing 20 away from a seat 10. When the occupant has entered the vehicle, the slider 50 is driven rearward so that the webbing 20 is moved toward the seat 10 to fasten the occupant. Movement of the slider 50 is controlled by detecting opening or closure of an associated door. Incidentally, numeral 14 indicates a drive unit for driving the drive member. The drive member extends through an outer tube 15 from the drive unit 14 to an anchor 13, whereby the drive member is guided by the outer tube 15 therebetween. Tube brackets 16 which are discrete members are fitted on the outer tube 15 so as to secure the outer tube 15 on a vehicle body.
On both ends of the outer tube 15, slip-out portions are formed respectively. The slip-out portions extend out in the form of a protuberance from an outer peripheral wall of the outer tube 15 and are attached to the anchor 13 and drive unit 14 respectively. Due to this structure, the tube brackets 16 must be fitted on the outer tube 15 before the slip-out portions are formed. This structure involves a potential problem that the outer tube 15 cannot be mounted on the vehicle body if the brackets 16 are fitted in a wrong direction or are accidentally omitted.
In addition, the tube brackets 16 move downwardly when the outer tube 1 is held upright subsequent to the application of the brackets 16 to the outer tube 15. It has hence been necessary to lift the brackets 16 to their attachment positions upon mounting the outer tube 15 on the vehicle body. Accordingly, additional mounting steps are required and the mounting work was cumbersome. It may be contemplated of winding tapes on the outer tube 15 to prevent the brackets 16 from moving downward. This solution however leads to a increase in the mounting cost.